The fly in the ointment is rail fares, which don't fall under Transport for London (TfL). To freeze these fares, the Department for Transport would have to compensate rail companies — which is highly unlikely to happen.

TfL confirmed today, at a session in front of the London Assembly, that the fares freeze will cost around £640m over four years, not the £1.9bn over five years figure bandied around during the election. It's now clear that this will apply to buses and single fares only.

Travelcards could rise by inflation plus 1% a year if no extra government funding is forthcoming. This has happened for the last few years — let's see if they're up for continuing that policy under Sadiq Khan.

This tweet from BBC correspondent Tom Edwards shows what was promised in Khan's election manifesto:

Page 8 Mayor's manifesto : "Londoners won't pay a penny more for their travel in 2020 than they do today" pic.twitter.com/bG6ni3GBzw